Damage or disease may affect the somatosensory nervous system and may cause neuropathic pain. Abnormal sensations or pain from normally non-painful stimuli may be associated with neuropathic pain and may occur episodically or continuously. Neuropathic pain sensations may include feelings of “stabbings” or “electric shocks”, burning, coldness, numbness, itching, and “pins and needles”. Common types of neuropathic pain include fibromyalgia, sciatica, diabetic neuropathy, chemo-induced neuropathy, shingles, HIV-induced neuropathy, and neuropathy from injury.